Helper arm for a rim holding tire changer

Abstract

A helper arm for use in conjunction with a rim-holding tire changer for assisting with the mounting/demounting of a tire. The helper arm comprises an arm having one end attached to a support device and an opposite end operably attached to an adjustable vertical member. The arm is preferably jointed and pivotally attached to the support device. Controls are provided to enable vertical adjustment of the vertical member. The vertical member may comprise a cylinder assembly having a cylinder shaft that may be moved up or down into operable engagement with the tire and wheel rim. A contact block is attached to the lower end of the cylinder. The contact block includes an attachment head configured to enable attachment of the block to the vertical member. Further, the contact block includes a shoulder having a rim-stop surface, a hook member opposite the shoulder, a heel extending downwardly from the body of the block and an instep along the underside of the block.

What is claimed is:  
     
       1. A contact block for use in conjunction with an arm operably attached to a rim-holding tire changer, the contact block comprising: 
       a body having an attachment head extending from the body and configured for operable attachment to the arm;  
       a shoulder having a surface for engaging the rim flange of a wheel;  
       a hook member extending from the body opposite the shoulder;  
       a heel extending downwardly from the body; and  
       a ramped surface extending along the underside of the body between the heel and the hook member; and  
       wherein the body is configured to operably engage a tire and a wheel rim during the mounting and de-mounting of the tire.  
     
     
       2. The contact block of claim  1 , wherein the ramped surface is concave. 
     
     
       3. A tire changer apparatus, comprising: 
       a base;  
       a rotatable tire holder mounted on the base;  
       a support tower extending upward from the base;  
       a swing arm pivotally attached to the support tower;  
       a vertically adjustable tire changing toolhead, extending downward from the swing arm;  
       a jointed helper arm assembly pivotally attached to the support tower and pivotable independently of the swing arm, the jointed helper arm assembly having a distal end;  
       a powered cylinder attached to the distal end of the jointed helper arm assembly and extending downward therefrom; and  
       a contact block attached to the powered cylinder for engaging a side wall of a tire supported on the rotatable tire holder to aid in mounting and demounting the tire.  
     
     
       4. The apparatus of claim  3 , wherein the contact block further comprises: 
       a body having an attachment head configured for mounting the block to the vertical member;  
       a shoulder protruding from the body for engaging the rim flange of a wheel;  
       a hook member positioned opposite the shoulder;  
       a heel extending downwardly from the body for depressing the bead of a tire; and  
       an instep extending along a bottom surface of the body.  
     
     
       5. The apparatus of claim  3 , wherein: 
       a pivotal axis of the swing arm relative to the support tower is vertical.  
     
     
       6. The apparatus of claim  5 , wherein: 
       a pivotal axis of the jointed helper arm assembly relative to the support tower is coaxial with the pivotal axis of the swing arm.  
     
     
       7. The apparatus of claim  3 , wherein: 
       a pivotal axis of the jointed helper arm assembly relative to the support tower is vertical.  
     
     
       8. The apparatus of claim  3 , wherein: 
       the jointed helper arm assembly includes a first arm member pivotally attached to the support tower, and a second arm member pivotally attached to the first arm member, so that the contact block supported from the jointed helper arm assembly can move with a tire rotating on the rotatable tire holder.  
     
     
       9. The apparatus of claim  3 , wherein: 
       the jointed helper arm assembly is vertically fixed relative to the support tower.